include/net/gre.h

   1 #ifndef __LINUX_GRE_H
   2 #define __LINUX_GRE_H
   3
   4 #include <linux/skbuff.h>
   5 #include <net/ip_tunnels.h>
   6
   7 #define GREPROTO_CISCO          0
   8 #define GREPROTO_PPTP           1
   9 #define GREPROTO_MAX            2
  10 #define GRE_IP_PROTO_MAX        2
  11
  12 struct gre_protocol {
  13         int  (*handler)(struct sk_buff *skb);
  14         void (*err_handler)(struct sk_buff *skb, u32 info);
  15 };
  16
  17 struct gre_base_hdr {
  18         __be16 flags;
  19         __be16 protocol;
  20 };
  21 #define GRE_HEADER_SECTION 4
  22
  23 int gre_add_protocol(const struct gre_protocol *proto, u8 version);
  24 int gre_del_protocol(const struct gre_protocol *proto, u8 version);
  25
  26 struct gre_cisco_protocol {
  27         int (*handler)(struct sk_buff *skb, const struct tnl_ptk_info *tpi);
  28         int (*err_handler)(struct sk_buff *skb, u32 info,
  29                            const struct tnl_ptk_info *tpi);
  30         u8 priority;
  31 };
  32
  33 int gre_cisco_register(struct gre_cisco_protocol *proto);
  34 int gre_cisco_unregister(struct gre_cisco_protocol *proto);
  35
  36 int gre_offload_init(void);
  37 void gre_offload_exit(void);
  38
  39 void gre_build_header(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
  40                       int hdr_len);
  41
  42 static inline struct sk_buff *gre_handle_offloads(struct sk_buff *skb,
  43                                                   bool gre_csum)
  44 {
  45         return iptunnel_handle_offloads(skb, gre_csum, SKB_GSO_GRE);
  46 }
  47
  48
  49 static inline int ip_gre_calc_hlen(__be16 o_flags)
  50 {
  51         int addend = 4;
  52
  53         if (o_flags&TUNNEL_CSUM)
  54                 addend += 4;
  55         if (o_flags&TUNNEL_KEY)
  56                 addend += 4;
  57         if (o_flags&TUNNEL_SEQ)
  58                 addend += 4;
  59         return addend;
  60 }
  61
  62 static inline __be16 gre_flags_to_tnl_flags(__be16 flags)
  63 {
  64         __be16 tflags = 0;
  65
  66         if (flags & GRE_CSUM)
  67                 tflags |= TUNNEL_CSUM;
  68         if (flags & GRE_ROUTING)
  69                 tflags |= TUNNEL_ROUTING;
  70         if (flags & GRE_KEY)
  71                 tflags |= TUNNEL_KEY;
  72         if (flags & GRE_SEQ)
  73                 tflags |= TUNNEL_SEQ;
  74         if (flags & GRE_STRICT)
  75                 tflags |= TUNNEL_STRICT;
  76         if (flags & GRE_REC)
  77                 tflags |= TUNNEL_REC;
  78         if (flags & GRE_VERSION)
  79                 tflags |= TUNNEL_VERSION;
  80
  81         return tflags;
  82 }
  83
  84 static inline __be16 tnl_flags_to_gre_flags(__be16 tflags)
  85 {
  86         __be16 flags = 0;
  87
  88         if (tflags & TUNNEL_CSUM)
  89                 flags |= GRE_CSUM;
  90         if (tflags & TUNNEL_ROUTING)
  91                 flags |= GRE_ROUTING;
  92         if (tflags & TUNNEL_KEY)
  93                 flags |= GRE_KEY;
  94         if (tflags & TUNNEL_SEQ)
  95                 flags |= GRE_SEQ;
  96         if (tflags & TUNNEL_STRICT)
  97                 flags |= GRE_STRICT;
  98         if (tflags & TUNNEL_REC)
  99                 flags |= GRE_REC;
 100         if (tflags & TUNNEL_VERSION)
 101                 flags |= GRE_VERSION;
 102
 103         return flags;
 104 }
 105
 106 #endif